Stephen l



Nov. 27 1923, 1,475,644

s. L. MERSHON IGNITING DEVICE FOR FUEL BURNERS Filed Jan. 17, 1925INVENTOI? hr TORNEYS Patented Nov. .27, 1923.

STEPHEN L. MERSHON, OF LLANEECH, PENNSYLVANIA.

IGNITIHG DEVICE FOE FUEL Application filed. January 17, 1923. Serial 1%.613,118.

To all whom it may cancer Be it known that STEPHEN L. MER- SHON, acitizencof the United States, and a resident of Llanerch, in the countyof Dela- 5 were and Stateof Pennsylvania, have invented -certainnew anduseful improve ments in Igniting Devices'for Fuel Burners, of which thefollowing is a specification.

My invention relates'to devices for igniting fuel projected into a potor burner in the form of a very fine spray, and particularly tothoseburners wherein the fuel employed is a heavy oil which does not readilyignite at low temperatures. My invention has particular reference tothose oil fuel burners which are used for domestic heating purposes,although my invention may be readily used Without substantial change forigniting heavy oil burners which are used in power. plants, or in anyplace where a spray of fuel having a high ignition point automaticallylighted and extinguished, and may times remain extinguished long enoughto allow the pot or burner to become quite cold.

l fhen a liquid fuel burner has been extinguished; for some time, andthe burner or pot is cold, great di'liiculty is frequently experiencedin igniting the cold fuel projected into the burner as a fine spray ofheavy cold oil. The ignition point of such oil is relatively high thatis to say, it must be heatedconsiderably before it readily ig nites orburns, and although burners may be provided with a pilot light by meansof which a small flame is kept continually burning within the pot orburner, such pilot light will not, under the conditions stated,accomplish the purpose for which it is intended, that is to say, it willnot ignite the spray of heavy fuel.

Fuel is sprayed into the burner or pot at a relativelyhigh velocity inminute particles by means of an air blast. It may he therefore that theparticles are driven through the flame of the pilot light so rapidlythat the temperature thereof is not raised to the ignition point. Theparticles do not probably remain in the flame long enough to becomeheated to the ignition point of the oil. But whatever may be thecausethe result is that the pilot light will not ignite the fuel, or,rather cannot be depended upon to ignite the fuel. It is generallynecessary to put paper or kindling into the burner, efore projectingsprayed fuel into the burner, in order to insure the ignition of thefuel when the burner is cold. lt'will also be obvious that it will beuneconomical and impractical to supply the pilot light with enoughilluminating gas to continually maintain a flame great enough to ignitecold sprayed fuel.

The object of my invention isto provid an oil burner of the type abovedescribed with a device which will insure theimmediate ignition of acold oil fuel sprayed into a coldL burner, provided with the ordinarysmall pilot light flame lrept burnin tiercin.

Referring to the drawing forming a part of this s, ecification, and inwhich the same reference characters employed thrcnighout the variousviews to designate the same parts, Fig. l is a plan view of an oilburner designed for domestic purposes located in the fire-box of adomestic boiler or waterheater, the part of the boiler or heaterstructure immediately above the burner being shown in section onthe line1-l of Fig. 2; and 2 is a vertical. sectional view of the boiler orheater structure, and through the pot or burner of an oil burningapparatus, showing my invention applied thereto, the atomizer orspraying device being conveniently shown in side elevation.

in the drawings a heavy oil burner is shown. In this burner a suitablefan (not shown) is mounted in the fan casing l and this fan isdriven bya shaft 2 preferably directly coupled to anelectric motor (not shown).When the-burner is not being used the current supplying the energy tothe electric motor is automatically out off so that the motor and fanare not in motion, and when the temperature of the room or space beingheated by the heater falls below a certain predetermined temperature,the current supplying energy to the motor is automatically closed by athermostatic regulator,

and the motor is driven, the fan revolved and a heavy liquid fuel ispumped or admitted by the pipe 3 to th nozzle 4 of the atomizer, whencethe fuel is projected into the pot or burner 5 as a very fine spray intimately ixed with air. A. supplemental air-pipe 6 may also communicateat one end with the fan casing l and at its other end open tangentiallyinto the pot othrough the opening 7 for the purpose of giving a whirlerwhen the pot is cold.

ing or circular motion to the atomized fuel in the pot. In some burners,however, this supplemental air-pipe may be omitted and all the air thatis supplied to the burner enters with the fuel through the nozzle 4:. Myinvention is equally adaptable to both types of burners.

lVithin the pot 5 is a pilot light 8. Illuminating gas is supplied tothe burner of the pilot light and a small flame is kept con tinuallyburning within the pot 5.

So far, I have described a heavy fuel burner and pilot light in which myinvention may be used but my invention is not to be construed as limitedto any particular form or type of burner other than one in which a fuelis projected as a fine spray into a pot which may at times be cold andwherein a pilot light is kept continually burning.

In such constructions it is very difficult to ignite the atomized fuelin starting the burn- JVhen the cold sprayed fuel is projected into thepot, the heat from the weak pilot light is insufficient to ignite itand, indeed, care has to be taken to make sure that the draft caused bythe rush of the incoming fuel does not in fact e2;- tinguish the pilotlight.

I have discovered, however, that if I suspend or mount a relativelysmall body of spherical or other suitable shape and preferably composedof heat conductive material, in such proximity to the flame of arelatively small pilot light, that the said light keeps the ball or bodyrelatively hot, an incoming cold charge of sprayed heavy fuel willinvariably and almost immediately ignite. I am not certain as to what isthe exact cause or reason for this immediate ignition. It may be becausethe relatively large surface of the relatively warm or hot body servesto quickly raise the temperature of all the particles of fuel, whirlingaround in the pot, to a point where the pilot flame will ignite them; orit may be that certain of the minute particles of heavy fuel are projected upon and remain on the surface of the relatively warm body, andare retained there long enough to absorb heat from the warm ball or bodysufficient to raise the temperature thereof up to a point where the weakpilot light flame will ignite them and that the other particles,whirling around within the pot, are ignited by the combustion of theparticles on the ball or body; or it may be that the liquid sprayed'uponthe spherical body forms drops which run down over the ball to the underside thereof, over or in the flame of the pilot light, and remain therelong enough to ignite, and that the heat of the burning drop or drops iscommunicated to particles whirling around within the pot to ignite them.I am inclined to think that possibly the latter theory may be the mostnearly correct one, but the ignition is so rapid that I am not yetcertain as to just what action does take place within the pot, and Itherefore do not wish to be construed as limiting my device to anyparticular mode of operation.

This ball or hot body 9 may be mounted at the end of a rod 10, passingthrough a horizontal transverse bar 11 resting across the top of themouth of the burner or pet 5, and having a nut 12 threaded over theupper end thereof for the purpose of adjusting the distance between theball 9 and the pilot light burner 8. It is obvious, however, that thisball 9 may be suspended over the flame of the pilot light 8 in anysuitable manner so long as itis in such a position as to be kept heatedby the flame of the pilot light, and be in the path of the fuel which isprojected into the pot. 5 from the atomizer or nozzle i. It is believedthat the operation of my device will now be apparent. Assuming the pot 5to be cold, the fan in the fan casing 1 to be not in motion and theflame from the pilot burner 8 to be continually ignited and in such aposition under the ball 9 as to keep the ball 9 relatively hot, and

assuming now that the burner is to be ignited, motion is communicated tothe fan in the fan casing 1 and finely divided or atomized liquid fuelis projected by the air blast suppliedby the fan, into the pot 5 throughthe nozzle 4:. Some of the particles of ignited fuel may strlke squarelyagainst the hot sphere or body 9; may almost immediately ignite, andtheir combustion may serve to so raise the temperature of the otherparticles in the pet that they also almost immediately ignite, and thepot and in fact, the space above the burner will be filled with flamingfuel. Or, if the other be the correct theory, the cold small particleswhirling around within the pot as delivered from the nozzle strikeagainst the hot ball or body 9' and the temperature of the wholewhirling mass of fuel is rapidly raised to such a temperature that thefeeble flame from the pilot light almost immediately ignites them; or itmay be that drops of liquid, collecting on the ball, run down to a pointover or in the flame, and burning there, seem to communicate the heat oftheir combustion to the incoming particles to ignite them.

But irrespective of what may be the controlling reason for the immediateignition of the atomized fuel, I have discovered that when a ball ofiron, or other suitable heatconductive substance, is suspended over thefeeble pilot light of a heavy oil burning burner and maintained hotthereby, the incoming cold fuel will ignite within a very few seconds.

The material of which this heated body is composed is preferably iron,although it ma be composed of any suitable material whic Y can bereadily heated by the flame of a pilot light and which will notdisintegrate under the high heat developed by the combustion of theatomized fuel when the burner is being operated.

It is also to be noted that the ball or mass of material forming theigniter should not be so attached or connected to the metal of theburner itself that heat will be conducted away from the ball to theburner. Some small metallic connection, such as the bolt or rod 10, or achain, may be used because such a relatively small metal connectionbetween the ball 9 and the pot 5 will not rapidly conduct heat away fromthe ball. To this extent then, the ball 9 may be said to besubstantially air-insulated or heat-insu lated from the pot or burner 5.

The size and shape of the mass which is suspended or mounted above thepilot may be varied in wide limits. I prefer, however, to use a ball, orspheroid, because thereon any liquid which might collect and run downthe sides thereof will be conducted to a single point, i. e., the lowestpoint of the ball, into the flame of the pilot-light, where it may berapidly heated and ignited by the pilot-light.

Having thus described my invention, what I claim and desire to protectby Letters Patent of the United States, is:

1. In a burner for atomized fuelcomprising a pot or burner, means toproject an atomized fuel into said burner and a pilot light in saidburner, the combination therewith of a body of material which will notmelt or disintegrate under the heat developed by the combustion of saidatomized fuel, mounted within said burner and maintained relatively hotby said pilot light atomized fuel into said burner and a pilot light insaid burner, the combination there-. with of a body of material whichwill not melt or disintegrate under the heat developed by the combustionof said atomized fuel, mounted within said burner and over or in theflame of said pilot light and maintained relatively hot by said pilotlight whenever atomized fuel is not being burned in said burner.

3. An igniter for burners adapted to consume an atomized fuelprojected'by an air blast into a pot or burner provided with a pilotlight, comprising a body of material which will not melt or disintegrateunder the heat developed by the combustion of said atomized fuel,mounted within and heat insulated from said burner and maintainedrelatively hot by said pilot light whenever atomized fuel is not beingburned within said burner.

4. In a burner for atomized fuel comprising a pot or burner, means toproject an atomized fuel into said burner and a pilot light in saidburner, the combination there with of a metal ball mounted within andsubstantially airinsulated from, and maintained in heated condition bysaid pilot light whenever atomized fuel is not being burned within saidburner.

In witness whereof, I have hereunto set my hand this sixteenth day ofJanuary, 1923.

STEPHEN L. MERSHON.

